Armour with large segments was definitely not unique to the lorica segmentata, as the Dendra Panoply shows: this does not mean that the Romans didn't come up with it on their own. They didn't even know about the Dendra suit, as it has been dated to 15th century BCE. Here are some pics



A possible clue is that 'segmentata' is not what the Romans called it at all: they may have called it lorica laminata, but it was latin-speaking scholars studying Trajans Column in the 16th century who named it 'segmentata'.